How do I know my center cap size?
The center cap size is the outer diameter of the decorative cap that sits in the wheel’s center opening, and it’s what you’ll need to match when buying a replacement. The simplest route is to check official specs for your wheel or measure the cap and bore with a caliper, then use those measurements to select a compatible cap.
Use official specifications to confirm size
This approach uses manufacturer-published specs or part numbers to determine the correct center cap size with the least ambiguity.
- Identify your wheel brand, model, and year, then look up the wheel spec sheet on the manufacturer’s site or in the owner’s manual. The center bore diameter and cap size are typically listed together.
- Search for the center cap part number that matches your wheel; many brands print a model or cap number on the cap or inside the wheel; use that to locate the exact size in the catalog.
- If you have the original center cap, check for its outer diameter printed on the edge or back of the cap.
- Check the wheel’s center bore size separately — the bore determines hub fit; ensure the cap’s inner hole or mounting surface matches the hub diameter if applicable.
- When in doubt, contact a dealer or wheel shop; they can pull the precise spec for your wheel and cap combination.
Official specs provide the most reliable size reference. If a cap size isn’t listed, move to measuring the bore and cap as described below.
Measure center bore and cap size yourself
Measuring with calipers lets you confirm the exact dimensions needed to select a matching center cap, especially when official data isn’t available.
- Measure the wheel’s center bore diameter with digital calipers by placing the jaws across the bore and reading the diameter. Record the size in millimeters (mm) or inches.
- Measure the center cap outer diameter by placing the cap on a flat surface and measuring from edge to edge across the widest point; this is the size most caps are sold by.
- Check the mounting method and ensure the cap will snap in or screw in as required; some caps rely on tabs, so a precise outer diameter is essential for a secure fit.
With these measurements, you can compare to cap listings or purchase caps by outer diameter that match the wheel’s center bore and hub.
Tips for compatibility and common pitfalls
Before buying, consider how your wheel is mounted and whether it is hub-centric or lug-centric, as this affects fit beyond just diameter.
- Hub-centric wheels rely on a precise center bore match to center the wheel on the hub; if the bore is larger than the hub, you may need a hub-centric ring, but the cap still must match the wheel opening.
- Some vehicles use OEM center caps that are specific to the wheel design; generic caps may not align logos or fit flush on that wheel family.
- When shopping online, confirm return policies and provide your wheel brand/model, year, and cap type to ensure compatibility; compare both bore and cap outer diameter.
These tips help ensure a secure, flush-fitting center cap aligned with your wheel’s design; when in doubt, consult the manufacturer or a professional installer.
Summary
To know your center cap size, start with official specs from the wheel or vehicle manufacturer and then verify by measuring the center bore and cap outer diameter if needed. Matching the cap outer diameter to the wheel’s center opening and ensuring the mounting method is correct will help you achieve a proper fit and look.
How do I know what size center caps I need?
You need to take three measurements for accuracy before buying the center cap, especially for aftermarket wheels. You need the inner diameter, the outer diameter, and the depth of the center cap. The inner diameter is the most important and basic measurement to get.
How to tell if the rim is 16 or 17?
Wheel you can see it says 17 first sometimes these numbers will be rearranged. But the 17 is the rim. Diameter. That's the diameter. Of this wheel. That's 17 in on this rim. It's an 18.
What size center cap for 18 inch rims?
There is no single center cap size for all 18-inch rims, as the correct size depends on the specific wheel model and its hub opening. Common sizes for 18-inch wheels include 65mm, 68mm, or 77mm (outside diameter), but the only way to know for sure is to measure your existing caps or the hub opening on the wheel itself.
How to determine the correct size
- Measure your current cap: If you have existing caps, use a ruler or measuring tape to find the outer diameter (across the face) and the inner diameter (the part that clips in). You can also measure the distance from clip to clip on the back of the cap.
- Measure the wheel's hub opening: If you don't have caps, carefully measure the diameter of the wheel's center hole where the cap should sit.
- Compare measurements: Check the specifications of potential replacement caps against your measurements. Many sellers will list the outer diameter and the clip-to-clip measurement.
- Check with the manufacturer: If you know the make and model of your wheels, it's best to check with the manufacturer or a specialized retailer for the exact part number and specifications.
Common sizes and examples
- 65mm (2.56 inches): A common size for some aftermarket and OEM wheels, such as certain Volk Racing TE37 models.
- 68mm (2.68 inches): Another popular aftermarket size, often seen in various styles.
- 77mm (3.03 inches): Used on some OEM applications, such as certain Chevrolet and GMC models.
- 63mm (2.5 inches): Found on specific vehicles, such as certain Dodge Ram 1500 models.
Are all car center caps the same size?
No, center caps are not all the same size; their size is determined by the specific wheel, not the vehicle. Factors like the wheel's hub diameter, bore diameter, and the design of the recessed area on the wheel face all dictate the correct cap size. You must measure the center hole or the recessed ring on your wheel to find the right cap, as common sizes can range from 50 to 75 mm in diameter.
How to find the correct center cap size
- Measure the wheel's center opening: Use a caliper to measure the diameter of the hole in the center of your wheel, or the diameter of the recessed ring where the cap sits.
- Measure your current cap (if applicable): If you have a cap that fits, measure its outer diameter and inner clip diameter.
- Check with the wheel manufacturer: For aftermarket or custom wheels, refer to the manufacturer's specifications to find the correct size and part number.
- Use online part databases: For OEM wheels, use online part databases to find the correct part number for your specific vehicle and wheel.
- Consider the wheel type: Some caps are designed for steel wheels, while others are made for alloy wheels, so ensure you choose the correct type for your wheel.
